The present invention relates to a needle assembly with a sliding needle sleeve to shield the sharp distal end of a needle. The needle assembly of this invention is similar to the inventor's previously patented needle assembly, U.S. Pat. 5,643,220. While maintaining the same concept of operation, this invention provides an alternative construction and design. This needle assembly, can be mounted on the forward end of a syringe body or other fluid delivery systems or reservoirs. A syringe utilizing this needle assembly offers protection to the user from unintended, accidental puncture.
It is well known that used syringe needles may cause serious illness or untimely death if a person gets accidentally scratched by a needle previously used on an infected individual. Paramedic and health care personnel in Emergency Room or in an emergency situation are particularly susceptible to receiving a scratch from a contaminated needle dislodged by the thrashing of an accident victim. Further, there has been a growing awareness of the danger of contracting AIDS, hepatitis or other known and unknown viral infections from improperly discarded hypodermic needles.
The needle covers currently used in the medical field employ a conventional needle that is completely shielded by a removable plastic cover. The plastic cover is manually removed before an injection and manually recapped after use. For example, to recap after an injection, the user has to retrieve the needle from the patient before covering the needle with the plastic cover. Consequently, accidental puncture can occur while the user retrieves the needle from a patient before the needle can be covered for protection. Accidental removal of the plastic cover is also possible when a covered needle is discarded which can prick or scratch a user or bystander.
There has been a number of attempts to design a needle cover with varying degrees of success. Most of these devices known in the art, apart from the invention filed by the same inventor, basically consist of two cylindrical components, with one sliding over or inside the other in a telescopic manner aided by a spring mechanism for automatic shielding and exposure of the needle. These needle covers differ in their locking mechanism. These covers are either hard to assemble due to the complexity of the mechanism or are expensive to manufacture.
It is a prime object of the present invention to provide a needle assembly which can protect the sharp tip of the needle from exposure prior to and during the mounting of the needle into the syringe body, between injections and after the needle has been discarded.
It is another object of the present invention to provide a needle assembly that is simple in design, utilizing less plastic material and easy to manufacture.
It is a further object of the invention to provide an inexpensive needle assembly that can be offered as a disposable product.